Sea Level and Chlorophyll-a Variability in the Kuroshio Extension from Altimeter and SeaWiFS

Ten years (1998-2007) of Sea Level Anomaly (SLA) from multiple satellite altimeters and chlorophyll-a concentration from the Sea-viewing Wide Field-of-view Sensor (SeaWiFS) are used to investigate the spatial and temporal variability of SLA and chlorophyll-a concentration. Seasonal SeaWiFS chlorophyll-a concentrations cycles and annual changes of altimeter SLA are derived for the subtropical North Pacific near 35°N and along the KE axis. Multi-time scale variability is found using the empirical orthogonal function (EOF) analysis. Spatial structure of SeaWiFS, is determined as the deviations from a local seasonal cycle and examined in relation to altimeter eddy structure. In the KE region, SeaWiFS structure is evident during the spring bloom period with a scale around 460 km. Eddy propagation speeds and scales are examined. Cold-core (cyclonic) rings correspond to areas of high SeaWiFS chlorophyll-a. Warm-core (anticyclonic) rings relate to areas of low chlorophyll-a concentration. SeaWiFS chlorophyll-a anomalies and altimeter SLA structure have an overall negative correlation. Our analysis also shows interannual variability on the chlorophyll-a concentration.